Will I need to reprep the factory mounting surface before bolting this on?

Check your engine bay for carbon buildup or old gasket material on the head flange — scrape it clean for a solid seal. The manifold itself bolts straight to factory points.

Do I need to source exhaust gaskets separately?

Yes. Gaskets are not included with the manifold. Grab a fresh set rated for stainless to ensure a leak-free seal.

Can I reuse this manifold if I swap turbos later?

Absolutely. As long as your next turbo has a TD05 flange, this manifold stays in the game. That's the real value of a flange-specific design.